1. Field of the Invention
The present invention relates to a hypertext displaying apparatus for displaying information acquired from a server as images on a screen, and more particularly, to a hypertext displaying apparatus which is capable of displaying such images in accordance with a history thereof.
2. Description of the Background Art
Recent advances in information technologies have made it possible for a user of such technologies to instantaneously acquire various information over the Internet by designating an address such as a URI (Uniform Resource Identifier) of a location which the user desires to access. Such information may be in the form of images, text, and/or sounds, etc. The acquired information is typically in the form of a hypertext described in HTML (HyperText Markup Language), etc. By using a hypertext displaying apparatus, which runs a program generally referred to as a “browser”, a user can request to acquire hypertext data from a server and display the hypertext data acquired from the server as an image on the screen. Examples of conventionally available browsers include Netscape Navigator® and Internet Explorer®.
Conventional hypertext displaying apparatuses are capable of retaining an order in which a number of images are displayed. The order may be referred to as history information. When a user presses a “previous” button, the hypertext displaying apparatus redisplays the most recently displayed hypertext data. When a “forward” button is further pressed while an image in response to the “previous” button is being redisplayed, the hypertext displaying apparatus redisplays the originally-displayed hypertext data, i.e., the hypertext data which was being displayed before the pressing of the “previous” button.
In early days, such hypertext displaying apparatuses were mostly implemented by means of personal computers or the like. Recently, however, mobile terminals for personal use, e.g., mobile phones, are being used increasingly more to implement hypertext displaying apparatuses. Such mobile terminals allow users to access the Internet by wire or wireless, and acquire information as desired.
FIG. 20 is a diagram illustrating a transition of exemplary images which may be displayed by a conventional hypertext displaying apparatus in the form of a mobile terminal. This conventional hypertext displaying apparatus includes a “previous” button, a “forward” button, and a “menu” button. The “previous” button and the “forward” button are used for displaying data on a screen in accordance with a displaying history thereof. The “menu” button is used to display a menu image for allowing a user to select from various functions.
In (a) of FIG. 20, the mobile terminal is shown as displaying an image of a content on the screen. Hereinafter, a hypertext displaying apparatus or an image displayed thereon will be said to be in a “normal display mode” when the hypertext displaying apparatus is displaying an image representing a content acquired fresh from a server on a network, i.e., as opposed to any data stored in the hypertext displaying apparatus. Next, if a user selects a link destination (i.e., “weather” in this example), the hypertext displaying apparatus acquires new hypertext data which is provided at the link destination over the Internet, and displays an image representing the newly acquired data (see (b) of FIG. 20). If the user selects a further link destination (i.e., “Hokkaido” in this example), the hypertext displaying apparatus newly acquires further hypertext data, and displays an image representing the acquired data (see (c) of FIG. 20). The hypertext displaying apparatus temporarily stores any hypertext data which were once acquired under the normal display mode into a cache memory, in the order in which the hypertext data were displayed.
As shown in (a) to (c) of FIG. 20, if the user presses the “previous” button at any point under the normal display mode, the hypertext displaying apparatus retrieves from the cache memory the data (if any) which was most recently being displayed on the screen just prior to a currently-displayed hypertext data, and displays an image representing the retrieved data. If the user presses the “forward” button at any point under the normal display mode, the hypertext displaying apparatus retrieves from the cache memory the data (if any) which has been displayed on the screen immediately after the currently-displayed hypertext data, and displays an image representing the retrieved data.
Thus, by pressing either the “previous” button or the “forward” button, the user can easily allow once-displayed hypertext data to be redisplayed on the screen.
As shown in (d) of FIG. 20, if the user presses the “menu” button, the hypertext displaying apparatus displays a menu image for allowing the user to select from various functions.
In order to realize the function of allowing hypertext data which has once been downloaded from a server to be viewed at any time, the hypertext displaying apparatus includes a memory for retaining such hypertext data as “stored data”. As a result, the user can read any desired data that is in the memory, whereby it becomes possible to obtain desired information faster than having to access the Internet to newly acquire it. Even if any content data on a server is deleted for some reason, the content data, once stored, can always be later viewed as stored data. Furthermore, the stored data will remain stored even after the hypertext displaying apparatus is turned off (unlike any downloaded data which is temporarily-stored in a cache memory, which will be lost once the apparatus is turned off), so that the stored data can be viewed the next time the hypertext displaying apparatus is turned on.
FIG. 21 is a diagram illustrating a transition of exemplary images that are displayed by the conventional hypertext displaying apparatus when stored data is read. First, as has been described with reference to FIG. 20, a user presses the “menu” button to evoke a menu image (see (a) of FIG. 21). Next, the user selects “stored data” in the menu image. As a result, the hypertext displaying apparatus displays a listing of stored data (see (b) of FIG. 21).
If the user selects an item corresponding to desired information in the image of the listing of stored data, then the hypertext displaying program reads the stored data concerning that information from the memory, and displays an image representing that information (see (d) of FIG. 21). Hereinafter, when a hypertext displaying apparatus is displaying an image representing stored data, the hypertext displaying apparatus or the displayed image will be said to be in a “stored data display mode”.
If the user presses the “forward” button under the stored data display mode, then the hypertext displaying apparatus displays an image representing the stored data (if any) which lies immediately subsequent to the currently-displayed stored data, in accordance with the order described in the stored data listing (see (e) of FIG. 21). If the user presses the “previous” button, then the hypertext displaying apparatus displays an image representing the stored data (if any) which lies immediately previous to the currently-displayed stored data, in accordance with the order described in the stored data listing (see (c) of FIG. 21).
Thus, the user can allow a number of stored data to be displayed on the screen one after another in the aforementioned manner. If the user selects a link destination indicated in any given stored data under the stored data display mode, then the hypertext displaying apparatus accesses that link destination over the Internet to newly download hypertext data therefrom, and the downloaded hypertext data is displayed on the screen (see (f) of FIG. 21). Thus, starting from the stored data, the user can obtain more detailed information. Once hypertext data has been newly downloaded over the Internet, the hypertext displaying apparatus switches its display mode from the stored data display mode to the normal display mode.
As described above, mobile terminals having a function of retaining once-acquired information as stored data are becoming increasingly more prevalent. One example is a class of mobile phones which are designed to support i-mode® services. A function which is provided in such mobile phones, called “screen memo”, corresponds to the aforementioned function of retaining stored data.
However, since the screen of a mobile terminal is generally small, it is practically impossible to have any stored data and newly-downloaded content displayed together within the same image. Therefore, if a user who has selected a link destination indicated in given stored data to download new hypertext data later desires to redisplay the given stored data, the user must access a listing of stored data from the menu image to recall the stored data. Especially if there is a very large number of stored data, it may be difficult to successfully reselect once-displayed stored data.
As mentioned above, the hypertext displaying apparatus has the function of displaying previous and/or subsequent images in accordance with a history thereof by pressing the “previous” button and/or the “forward” button. This function may mislead the user into believing that he or she should be able to redisplay the stored data as well, by similarly operating the “previous” button and/or the “forward” button. In actuality, however, the aforementioned function alone does not allow the once-displayed stored data to be redisplayed. In this respect, the conventional hypertext displaying apparatus has a problem in that a user thereof cannot operate the apparatus in an instinctive manner, but rather feels that the required operation is cumbersome.
FIG. 22 is a diagram illustrating a transition of exemplary images displayed by the conventional hypertext displaying apparatus, which better describes the problem associated therewith. Descriptions of any portions overlapping with the operations already described with reference to FIGS. 20 and 21 will be omitted. If the user designates a link destination “Cantonese cuisine” indicated in the stored data (see (a) of FIG. 22), the hypertext displaying apparatus displays detailed information associated with this link destination (see (b) of FIG. 22). In (b) of FIG. 22, the user will instinctively feel that the image of (a) will be redisplayed after pressing the “previous” button. In actuality, however, pressing the “previous” button will only result in the image of (c) being displayed because the image of (c) is stored in the cache memory of the hypertext displaying apparatus.